Herbicidal 5,6-disubstituted-benzoisoxazole-4,7-diones

ABSTRACT

Benzo(d)isoxazole-4,7-diones, and substituted in the 5- and 6positions, are used for the control of weeds.

United States Patent Entwistle et al.

[451 Oct. 21, 1975 HERBICIDAL 5,6'DISUBSTITUTED-BENZOISOXAZOLE- 4,7-DIONES Inventors: Ian D. Entwistle; Peter J. Williams; Barry R. J. Devlin, all of Sittingbourne, England Assignee: Shell Oil Company, Houston, Tex.

Filed: Sept. 4, 1973 Appl. No.: 393,770

Related U.S. Application Data Division of Ser. No. 112,400, Feb. 2, 1973, Pat. No. 3,780,055.

Foreign Application Priority Data Feb. I7, 1970 United Kingdom 7527/72 [52] U.S. Cl 260/307 D OTHER PUBLICATIONS Quilico et 211., CA. 45, 606e (1951).

Primary ExaminerRaymond V. Rush [57] ABSTRACT Benzo(d)isoxazole-4,7-diones, and substituted in the 5- and 6- positions, are used for the control of weeds.

4 Claims, N0 Drawings HERBICIDAL 5,6-DISUBSTITUTED-BENZOISOXAZOLE-4,7-

DIONES This is a division of application Ser. No. 112,400, filed Feb. 2, 1973, now [1.8. Pat. No. 3,780,055.

FIELD OF THE INVENTION This invention relates to the use as herbicides of novel 5,6-disubstituted-lH-indazole-4,7-diones, 5,6- disubstituted-benzo(d)isoxazole-4,7-diones, 5,6- disubstituted-benzo(d)tria2ole-4,7-diones, and 5,6-di substituted-benzimidazole-4,7-diones.

DESCRIPTION OF THE PRIOR ART No pertinent art is known.

SUMMARY OF THE INVENTION DESCRIPTION OF PREFERRED EMBODIMENTS The novel 4,7-diones of this invention are represented by the following general formula:

wherein X and Y each independently represents middle halogen, i.e., chlorine or bromine, an alkoxy group of I to 6 carbon atoms, such as ethoxy, an amino group, an amino group mono or di-substituted by alkyl or cycloalkyl of up to 6 carbon atoms, for example methyl, ethyl, isopropyl, sec-butyl or cyclopropyl, or by carbamoyl-substituted alkyl of up to 12 carbon atoms, for example N-methylcarbamoylethy], or by acyl of up to 6 carbon atoms, such as acetyl or by nitroso, and A, together with the two carbon atoms of the quinone ring to which it is attached represents a pyrazole, isoxazole or triazole ring each substituted by alkyl of 1-6 carbon atoms, for example methyl, isopropyl or trifluoromethyl.

In view of their herbicidal spectra, the following compounds are particularly preferred:

6-isopropylamino-5-(N-acetyl-N-methylamino)-lmethyl-l H-indazole-4,7-dione, 6-isopropylamino- 1 methyl--(N-acetyl-N-methylamino) benzimidazole- 4,7-dione.

The novel compounds of the invention wherein X and Y represent halogen and A, together with the two carbon atoms of the quinone ring to which it is attached, represents an alkyl substituted isoxazole or pyrazole ring are prepared by reacting a 2,3- dihalobenzoquinone of the formula:

with either a diazo compound of formula:

RCHN2 (Ill) wherein R represents a hydrogen atom or an alkyl group, or with a nitrile oxide of formula:

R2CN- 0 (IV) wherein R represents an alkyl group, particularly methyl. The reaction with the diazo compound is preferably carried out in an organic solvent such as ether and the reaction with the nitrile oxide may be carried out in an aqueous medium.

Other compounds of Formula I wherein X and Y each represents a halogen atom are obtained by reacting a compound of formula:

wherein R represents a hydrogen atom or an alkyl group, preferably methyl, with the appropriate elemental halogen, for example gaseous chlorine or liquid bromine. The reaction is preferably carried out in an organic solvent such as glacial acetic acid or an alcohol, for example methanol.

Those compounds of formula I wherein X and/or Y represents an amino group optionally mono-substituted by alkyl, acyl-substituted alkyl or cycloalkyl may be prepared by reacting a compound of formula I wherein X and/or Y represents a halogen atom with ammonia or the appropriate primary amine, suitably in an organic solvent such as ethanol or methylene chloride.

Those compounds of formula I wherein X and/or Y represents an acyl substituted amino group are prepared by reacting a compound of formula I wherein X and/or Y represents an optionally mono-substituted amino group with a suitable acylating agent such as an acid anhydride, for example acetic anhydride.

Those compounds of Formula I wherein X and/or Y represents a nitroso-substituted amino group are obtained by reacting the corresponding compound wherein X and/or Y represents a mono-substituted amino group, with nitrous acid in acidic aqueous solution.

As mentioned above the compounds of the invention exhibit herbicidal properties and are of particular interest as pre-emergence selective herbicides for combat ing weeds in sugar beet and rice crops.

The invention is further illustrated in the following examples. For certain of the compounds given below, which have non-identical groups at the 5- and 6- positions, the preparative procedure may give rise to the formation of the isomeric compound in which the positions of the two groups have been reversed. In most cases it is not known with certainty whether a single isomer or isomer mixture is obtained. For convenience,

therefore, the compounds have been named as single isomers.

EXAMPLE I 5,6-Dichloro-1-methyl-1H-indazole-4,7-dione 5 cit O 2,3-Dichlorobenzoquinone (22 grams) was added portionwise to a stirred solution of diazomethane (14 grams) in ether (500 milliliters) maintained at a temperature below 15C. A pale yellow solid separated out from the solution, and this was filtered off and dried to yield the desired product having a melting point of 176-177C.

Analysis:

Calculated for C H N O Cl C, 41.7; H, 1.7; N, 12.1; C1, 30.7%.

Found: C, 42.3; H, 1.7; N, 12.2; C1, 30.5%.

EXAMPLE I1 6-Chloro-5-cyclopropylamino- 1 -methyl-1 H-indazole- 4,7-dione 3O 5 ,6-Dichlorol -methyl-lH-indazole-4,7-dione (10 grams prepared as in Example I) and cyclopropylamine (10 grams) in ethanol (50 milliliters) were stirred together at room temperature for minutes. The precipitate formed was filtered off and dried to yield the desired product as a red solid having a melting point of 175-176C.

Analysis:

Calculated for c,,H,,,N o,c1; 16.7%.

Found: C, 52.5; H, 4.6; N, 16.4%.

EXAMPLE III C, 52.5; H, 4.0; N,

6-Chloro-5-(N-acetyl-N-cyclopropylamino)-l-methyllH-indazole-4,7-dione 6-Chloro-5-cycl0pr0pylamino-1-methyl-l H- indazole-4,7-dione (3 grams prepared as in Example 11) was added to acetic anhydride (10 milliliters) contain- EXAMPLE IV 6-Cyclopropylamino-5-(N-acetyl-N- cyclopropylamino 1 -methyl- 1 Hindaz'ole-4,7-dione 6-Chloro-5-(N-acetyl-N-cyclopropy1amino)-1- methyl-lH-indazole-4,7-dione (2 grams prepared as in Example 111) and cyclopropylamine (2 grams) in ethanol (25 milliliters) were heated together under reflux for 10 minutes. The solvent was then removed under reduced pressure and the residual red oil purified by chromatography on alumina using methylene chloride as eluant to yield th'e desired product having a melting point of 78C. I

Analysis: 1 Calculated for C, H, N O C, 61.1; H, 5.8; N,

Found: C, 60.4; H, 5.8; N, 17.4%.

EXAMPLE V I Reaction of 6-chloro-5-(N-acetyl-N-isopropylamino) l -methyl-l H indazole-4,7-dione with isopropylamine a. 6-Chloro-5-(N acetyl-N-isopropylamino)-1- methyl-1H-indazole-4,7-dione (3 grams prepared by a similar method to that described in Example 111) and isopropylamine (3 grams) in ethanol (25 milliliters) were heated together under reflux for 10 minutes. On cooling the reaction mixture a yellow-orange solid crystallized out, which was filtered off and dried to yield 6- ethoxy-5-(N-acetyl-N-isopropylamino)-1-methyl-1H- indazole-4,7-dione having a melting point of 154-155c.

Analysis:

Calculated For C H N O C, 59.0; H, 6.3; N, 13.8%.

Found: C, 59.0; H, 6.3; N, 13.7%.

b. 6-Chloro-5-(N-acetyl-N-isopropylamino)-1- methyl-lH-indazole-4,7-dione (3 grams) and isopropylamine (3 grams) in methylene chloride (25 milliliters) were heated under reflux for 15 minutes. The solvent was then removed under reduced pressure and the residue recrystallized from ethanol to give 6- isopropylamino-5-(N-acetyl-N-isopropylamino)-1- methyl-1H-indazole-4,7-dione as a red solid having a melting point of 123126C.

Analysis:

Calculated for C H N O 17.6%.

Found: C, 60.3; H, 6.7; N, 17.5%.

C, 60.4; H, 7.0; N,

EXAMPLE VI 6-Chloro-1-methyl-5-(Nitroso-N- methylamino)indazole-4,7-dione' 6-Chloro-5-methylamino- 1 -methylindazole-4,7- dione (4.5 grams) in 30% hydrochloric acid (50 milliliters was stirred at 0C and treated dropwise with a solution of sodium nitrite (3.0 grams) in water (20 milliliters). After 1 hour the orange solid which had separated out was collected,"washed with water and dried over silica gel to yield the desired product having a melting point of 124125C (with decomposition).

Analysis:

Calculated for C H N O Cl: C, 42.4; H, 2.8; N, 22.0%.

Found: C, 42.7; H, 2.9; N, 21.9%.

' EXAMPLE v11 5 ,6-Dichloro-3-meth ylbenzo(d)isoxazole-4,7-dione rated to dryness under reduced pressure and the resi-- CH Cl due treated with ethanol to yield to desired product as a yellow crystalline solid having a melting point of 254-255C.

\ Analysis: I

0 Cl Calculated for C-,H N O C1 C, 36.2; H, 1.3; N,

O 18.1; C1, 30.6%. Found: C, 36.2; H, 1.3; N, 17.9; C1, 30.9%. A solution of acetomtrile oxide was prepared by passing chlorine (10.8 grams) over 30 minutes into a stirred 10 EXAMPLE 1X suspension of acetaldoxime (9 grams) and sodium bi- 56 DibrOmO methyibenzimidazole 4 7 dione carbonate (25.2 grams) in water at 0C was added 2,3- a dichlorobenzoquinone (17.7 grams) portionwise over 0 minutes. The mixture was stirred at O-5C for 2 Cl hours and then extracted with methylene chloride. The 15 n dried extracts were evaporated to dryness under re- 1 duced pressure and the residue recrystallized from ethanol to give the desired product as yellow crystals having a melting point of 214-215C. CH

Analysis: M Calculated forC H NO Cl :C 41.5' H, 1.3- N, 6.0%.

8 3 3 2 4,7-D1methoxy-l-methylbenzimldazole (3.0 grams) Found: C, 41.9; H, 1.5; N, 6.0%. i

was added portionwise to a solution of bromine (10.0 EXAMPLE V111 grams) in methanol (20 milliliters) over a period of 10 minutes. The mixture was stirred for 1 hour at room -D' r -meth lbenzo d triazole-4,7-dione lchlo O l y temperature then poured mto water and the excess bromine removed by bubbling air through the mixture. The yellow precipitate obtained was filtered off and re- Cl crystallized from ethanol to give the desired product having a melting point of 250C (with decomposition). N Analysis:

\N Cl Calculated for C H N O Br C, 30.0; H, 1.3; N,

8.8%. 0 Found: C, 30.6; H, 1.4; N, 8.6%.

. 4,7-D1methoxybenzo(d)triazole (1.2 grams) in gla- EXAMPLE X cial acetic acid was warmed to C and chlorine gas Following procedures similar to those given in the was passed into the solution for 1 hour. The solution previous examples further compounds were prepared, was then poured into water and extracted with methywhose physical characteristics and analysis are set out lene chloride. The dried organic extracts were evapo- 40 in Table 1.

TABLE 1 Compound Melting Point "C Analysis 5amino-6-chloro-1-methy1- 285-286 Calculated for C,,H,N,O,C1; C 45.5; H 2.8; N 19.9; CI 16.8% 1H-indaz0le-4,7-dione Found: C 45.9; H 3.1; N 19.6; C1 16.7% 6-chloro-5-isopropylamino-1- 142-143 Calculated for CHHHNQOZCI: C 52.1; H 4.7; N 16.6; Cl methyl-lH-indazole-4.7-dione Found: C 52.1; H 47; N 16.4; C1 14.3% 6-isopropylamino-5-(N-acetyl- 188-189 Calculated for CNHHN4OJ: C 57.9; H 6.3; N 19.3% Nmethylamino)-1-methyl-1H- Found: C 57.2; H 6.0; N 19.0% indazole-4.7-dione 6-ch1oro-5-(N-acetyl-N-iso- 143-144 Calculated for C H N O CI: C 52.9; H 4.7; N 14.2% propylamino)-l-methyl-lH-indazole- Found: C 52.5; H 4.6; N 14.0% 4,7-dione 5-(N-acetyl-N-methylamino)-6- 182-183 Calculated for C,5H;9N5O,: C 54.0; H 5.8; N 21.0% (1-(N- Found: C 54.1; H 6.2; N 20.4% methylcarbarnoyl)ethyl)amino-1- methyl-1H-indazole-4,7-dione 6-cyclopropylamino-5-(N- 167-168 Calculated for C H N O C 58.3; H 5.6; N 19.4% acetyl-N-methylamino)-1-methyl- Found: C 58.2; H 59; N 19.2% 1H-indazole-4,7-dione V 6-cyclopropylamino-5-(N- 162-163 Calculated for C,5H,8N4O;: C 59.6; H 6.0, N 18.5% acety1-N-ethylamino)-1-methy1-1H- Found: C 59.6; H 6.3 N 18.0% indazole-4,7-di0ne 6-chloro-5-ethylamino-l- 147 Calculated for c..,H,,N,o,c1-. C 501; H 4.2; N 17.5% methy11H-indazole-4,7-dione Found: C 50.2; H 4.2; N 17.4% 6-methylamino-5-(N-acetyl- 209-210 Calculated for CHHHN4OJ: C 54.9: H 5.4, N 21.3% N-mcthylamino)-1-methyl-1H- Found: C 54.4; H 5.6; N 20.9% indazole-4,7-dione 6-methylamino-5-(N-acetyl- 163-165 Calculated for C,3H|GN4O;1 C 56.5; H 5.8; N 20.3% N-ethylamino)-l-methyl-lH- (dec) Found: C 56.8; H 6.0; N 20.0% indazolc-4,7-dione 5-amino-6-chloro-3-methyl- 222-223 Calculated for C H N O Ck C 45.2; H 24; N 13.2; C1 16.7% benzo(d)isoxazole-4,7-dione Found: C 45.6; H 26; N 13.1; C1 167% 5-(N-acctylamino)-6-chloro- 183-184 Calculated for C H N O,Cl: C 47.1; H 2.8; N 11.0% 3-methylbenzo(d)isoxazole4,7- Found: C 47.1; H 2.7; N 11.1%

dione TABLE l-Continued Compound Melting Point C Analysis 6-chlor0-5-methylamino-3- 195-196 Calculated for C H N O Cl: C 47.6; H 3.1; N 12.4% methylbenzo(d)isoxazole-4 7-dione Found: C 47.8; H 3.2; N 12.1% 6-isopr0pylamino5-(N- 186-187 Calculated for C H -,N;,O;: C 57.7; H 5.9; N 14.4% acetyl-N-mcthylamino)-3- Found: C 57.9; H 5.9; N 14.0% methylbenzo(d)isoxazole-4,7-dione 6-chloro-5-isopropylamino-3- 133-134 Calculated for CHHHNQOJ: C 51.9; H 4.3; N 11.0% methylbenzo(d)isoxazole-4,7-dione Found: C 52.0; H 4.3; N 10.7% 6-chloro-5-methylamino-l- 196-197 Calculated for C H N O Cl: C 42.4; H 3.1; N 24.7% methylbenzotriazole-4,7-dionc Found: C 42.1; H 3.3; N 24.8% 6-isnpropyl-l-methyl-5-(N- 164-165 Calculated for CHHHNSOQ: C 53.6; H 5.9% acctyl-N-methylamino)-benzo- (dec) Found: C 53.6; H 6.3% triazole-4,7 dione 6-ch1oro-5-isopropylamino-l- 106-107 Calculated for C H N;O Cl: C 47.2; H 4.3; N 22.0; CI 14.0% methylbcnzotriazole-4,7-dionc Found: C 46.8; H 4.4; N 21.8; C1 13.6% 6-isopropylarnino-5-(N- 179-181 Calculated for CHH2IN5OH: C 56.4; H 6.6; N 21.9% acctyl-N-isopropylamino)-1- (dec) Found: C 56.7; H 6.9; N 21.8% mcthylbenzotriazole-4,7-dionc fi-isopropylamino-l-mcthy1- 159-165 Calculated for CHHWN4O3: C 57.9; H 6.3; N 19.3% 5-(N-acetyl-N-methylamino)ben- Found: C 57.8; H 6.4; N 19.3% zimidazole-4,7-dione 6-chloro-S-isopropylamino- 169-170 Calculated for C H H o cl: C 51.8; H 4.7; N 16.4; CI 14.0% l-methylbenzimidazole-4,7-dionc Found: V 51.9; H 4.8; N 16.2; CI 13.8% 5,6-dibromo-2-trifluoro- 237-238 Calculated for CgHNgOgBl'zFaI C 25.7; H 0.7; N 7.5% methylbenzimidazole-4.7-dione Found: C 25.8; H 1.1; N 7.2% 6-bromo-5-methylamino-2- 230 Calculated for C H N O Br F;,: C 33.3; H 1.5; N 12.9% trifluoromethylbenzimidazole-4.7- dec Found: C 33.7; H 1.7; N 12.6% dione 5.6-dichlorobenzimidazole4.7- 330 Calculated for C H N O Cl C 38.7; H 0.9; N 12.8; C1 32.2% dione dec Found: C 38.9; H 1.0; N 12.4; C1 32.7% fi-isopropylamino-S-(N- 200 Calculated for C H N O F C 48.8; H 4.3; N 16.2% acetyl-N-methylamino)-2- dec Found: C 48.7; H 4.5; N 16.0% trifluoromethylbenzimidazole-4,7- dione 5,6-dichloro-I-methyl- 260 Calculated for C H N O Cl C 41.6; H 1.7; N 12.1% benzimidazole-4,7-dione dec Found: C 41.6; H 1.7; N 11.8% 1-methyl-6-(N-acetyl-N- 164-165 Calculated for CHM-211N403: C 59.2; H 6.6; N 18.4% methylamino)-5-S- Found: C 58.9; H 6.6; N 18.2% butylaminobenzimidazole-4 7-dione 5,6-dichloro-l-iso- 146-148 Calculated for cwHgNzozclgi C 46.4; H 3.1; N 10.8% propylbenzimidazole-4,7-dione Found: C 46.8; H 3.5; N 10.4%

EXAMPLE XI tests the acetone solutions were diluted with an equal I volume of water and the resulting formulations applied Herb'c'dal Actw'ty at two dosage levels corresponding to 10 and 1 kilo- To evaluate their herbicidal activity, the compounds grams of F matenal Pf hectare respectlvely f of the invention were tested using as a representative volume equwalem to 400 tel-s per hectare' ln the range of plants. maize Zea mays (M2); rice oryza 40 drench tests one volume of the acetone solution was disaliva (R); barnyard grass, Echinchloa crusgalli luted to 155 volumes with water and the resulting forpea Pisum San-Wm p linseed, Linum usimtissium mulation applied at one dosage level equivalent to 10 (L); mustard, Sinapl-S Elba (M); and Sugar beet Beta kilogram of active material per hectare in a volume vulgaris (SB). In the tests on one of the compounds rice equlvalent to approxlmately 3,000 hters per was replaced by oat Avena San-Va and barnyard grass In the pre-emergence tests untreated sown soll and 1n by ryegrass Loh-um perenne the post-emergence tests untreated SOll bearing seed- The tests fall into two categories, pre-emergence and Plants Y f used as controls post-emergence. The pre-emergence tests involved The hel'hlcldal effects f th Compounds were asspraying a liquid formulation of the compound onto the Sessed Y' Eel/en days after spraymg the fohhge and soil in which the seeds of the plant species mentioned drFhchmg the and eleven days after Pf y g: h above had recently been sown The post emergence S01], and were recorded on a 0-9 scale. A rating 0 n h tests involved two types of test viz so drench and cates no effect on the treated plants, a rating 2 111C11- liar spray tests. In the soil drench tests the soil in which cates a reduchoh fresh Welght ohstem 9"! leaf of the seedling plants of the above species were growing, was Plants of PP h y 25%, a 5 a drenched with a liquid formulation containing a comductloh of approximately 55%, a rating 9 Indicates a pound of the invention, and in the foliar spray tests the reduchoh of 95% seedling plants were sprayed with such a formulation. The results of the 1651.5 are Set out In Table The soil used in the tests was a steam-sterilized, mod- The novel compounds can be formulated as herbiified John Innes Compost mixture in which half the cidal compositions comprising a carrier or a surfacepeat, by loose bulk, had been replaced by vermiculite. active agent, or both a carrier and a surface-active age- The formulations used in the tests were prepared by nt, together with as active ingredient, at least one subdiluting with water and solutions of the compounds in stituted 1,4-quinone derivative of the invention. acetone containing 0.4% by weight of an alkylphenol- The term carrier" as used herein means a material, [ethylene oxide condensate available under the trade which may be inorganic or organic and of synthetic or name Triton X-155. In the soil spray and foliar spray 5 natural origin, with which the active compound is Table 5 -Continued POST-EMERGENCE (PLANTS) PRE-EMERGENCE (SEEDS) COMPOUND DOSAGE SOIL DRENCH DOSAGE FOLIARSPRAY SOlLSPRAY X kg/ha Mz R 80 P L M SB kg/ha Mz R BG P L M SB M2 R 80 P 1. M SB N(COCH3)CH 10 9 9 9 9 7 9 5 10 9 9 9 9 9 9 9 9 9 9 s 9 9 s 1 6 6 6 8 9 9 9 s 6 9 3 2 7 1 NHCH(CHq)2 I 0 0 1 0 0 0 0 10 0 0 3 2 9 8 3 0 5 9 0 0 7 1 1 3 1 6 6 2 0 0 0 0 NHCH(CH;)1 9 9 9 9 7 9 5 10 9 9 9 9 9 9 9 9 9 9 s 9 9 8 1 6 6 6 8 9 9 9 8 6 9 3 2 7 1 Cl 10 0 0 1 0 0 0 0 10 0 0 3 2 9 8 3 0 5 9 0 0 7 1 1 3 1 6 6 2 0 0 0 0 H CH;, 10 9 9 9 9 7 9 5 10 9 9 9 9 9 9 9 9 9 9 8 9 9 8 1 6 6 6 '8 9 9 9 8 6 9 3 2 7 1 H CH 10 0 u 1 0 0 0 0 10 o 0 3 2 9 s 3 0 5 9 0 0 7 1 mixed or formulated to facilitate its application to the plant, seed, soil or other object to be treated, or its storage, transport or handling. The carrier may be a solid or a fluid. Any of the material usually applied in formulating herbicides may be used as carrier.

Suitable solid carriers are natural and synthetic clays and silicates for example natural silicas such as diatomacious earths; magnesium silicates, for example, talcs; magnesium aluminum silicates, for example, attapulgites and vermiculites; aluminum silicates, for example, kaolinites, montmorillinites and micas; calcium carbonates; calcium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; elements such as for example, carbon and sulphur; natural and synthetic resins such as for example, coumarone resins, polyvinyl chloride and styrene polymers and copolymers; solid polychlorophenols; bitumens; waxes such as for example, beeswax, paraffin wax, and chlorinated mineral waxes; and solid fertilizers, for example superphosphates.

Examples of suitable fluid carriers are water, alcohols,such as for example, isopropanol, glycols; ketones such as for example, acetone, methyl ethyl ketone,

methyl isobutyl ketone and cyclohexanone; ethers; aro- 3 matic hydrocarbons such as for example, benzene, toluene and xylene; petroleum fractions such as for example, kerosene, light mineral oils; chlorinated hydrocarbons, such as for example, carbon tetrachloride, perchloroethylene, trichloroethane, including liquefied normally vaporous gaseous compounds. Mixtures of different liquids are often suitable.

The surface-active agent may be an emulsifying agent or a dispersing agent or a wetting agent; it may be nonionic or ionic. Any of the surface-active agents usually applied in formulating herbicides or insecticides may be used. Examples of suitable surface-active agents are the sodium or calcium salts of polyacrylic acids and lignin sulphonic acids; the condensation products of fatty acids or aliphatic amines or amides containing at least 12 carbon atoms in the molecule with ethylene oxide and/or propylene oxide; fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohols or alkyl phenols for example p-octylphenol or p-octylcresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as sodium dodecylbenzene sulphonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

The compositions of the invention may be formulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols. Wettable powders are usually compounded to contain 25, 50 or by weight of toxicant and usually contain, in addition to solid carrier, 3l0% by weight of a dispersing agent and, where necessary, O-10% by weight of stabilizer(s) and/or other additives such as penetrants or stickers. Dusts are usually formulated as a dust concentrate having a similar composition to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing /10% by weight of toxicant. Granules are usually prepared to have a size between 10 and BS mesh, and may be manufactured by agglomeration or impregnation techniques. Generally, granules will contain /z25% by weight toxicant and 010% by weight of additives such as stabilizers, slow release modifiers and binding agents. Emulsifiable concentrates usually contain, in addition to the solvent and, when necessary, cosolvent, 10-50% weight/volume toxicant, 2-20% weight/volume emulsifiers and 020% weight/volume of appropriate additives such as stabilizers, penetrants and corrosion inhibitors. Suspension concentrates are compounded so as to obtain a stable, non-sedimenting, flowable product and usually contain 10-75% by weight toxicant, 05-15% by weight of dispersing agents, O.ll0% by weight of suspending agents such as protective colloids and thixotropic agents, 0-1 0% by weight of appropriate additives such as defoamers, corrosion inhibitors, stabilizers, penetrants and stickers and as carrier, water or an organic liquid in which the toxicant is substantially insoluble; certain organic solids or inorganic salts may be dissolved in the carrier to assist in preventing sedimentation or as antifreeze agents for water.

The compositions of the invention may contain other ingredients, for example, protective colloids such as gelatin, glue, casein, gums, cellulose ethers, and polyvinyl alcohol; thixotropic agents, e.g., bentonites, sodium polyphosphates; stabilizers such as ethylene diamine tetra-acetic acid, urea, triphenyl phosphate; other herbicides or pesticides; and stickers, for example nonvolatile oils.

Aqueous dispersion and emulsions, for example, compositions obtained by diluting a wettable powder or an emulsifiable concentrate according to the invention with water, also lie within the scope of the present invention. The said emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick mayonnaise"-like consistency.

We claim as our invention:

1. A compound of the formula methylbenzo(d)isoxazole-4,7-dione. 

1. A COMPOUND OF THE FORMULA
 2. A compound as claimed in claim 1 wherein X represents chloro, bromo, amino, methylamino, dimethylamino or acetylamino; and Y represents chloro, bromo, or methylamino.
 3. A compound as claimed in claim 2 wherein X represents chloro, methylamino, dimethylamino or acetylaminO; and Y represents chloro or methylamino.
 4. 6-Isopropylamino-5-(N-acetyl-N-methylamino)-3-methylbenzo(d)isoxazole-4,7 -dione. 